1. Field of the Invention
The present invention relates to color correction for a display device and, more particularly, to a method for generating a lookup table for color correction for a display device.
2. Description of the Related Art
In manufacturing display devices such as liquid crystal displays (LCDs), it is generally very difficult for the manufactured display devices to have identical luminous ratios of red, green and blue primary light sources. As a result, the manufactured display devices cannot exhibit identical color performance even though they are manufactured in the same batch and the same process by the same manufacturer. Thus, the manufactured display devices must undergo a white balance adjustment before they become finished products.
Nowadays, a method for the white balance adjustment commonly used in manufacturing display devices includes the following steps. First, a half-black and half-white image signal is inputted to a display device to be adjusted. Next, an instrument is used to measure the image displayed on the display device to obtain deviations of chromaticity coordinates of bright and dark brightnesses with respect to the chromaticity coordinate of a reference white. Finally, according to the deviations, gain and offset parameters for the red, green and blue primary light sources are repeatedly adjusted to change driving voltages for the red, green and blue primary light sources to cause the white under the bright and dark brightnesses to be identical to the reference white.
However, the above method for the white balance adjustment only adjusts the white balance under the bright and dark brightnesses and results in inaccurate color temperatures for shades between, but not including, the bright and dark brightnesses, so that the adjusted display devices still cannot exhibit identical color performance. Moreover, the above method does not provide brightness curve adjustment for the display devices. In addition, today, the display devices each generally supports several video interfaces such as a video graphics array (VGA), a digital visual interface (DVI) and a high-definition multimedia interface (HDMI), and each video interface typically supports several color temperature modes such as cool (12000K), normal (9300K) and warm (6500K). If the white balance is manually adjusted interface by interface and mode by mode, it will take a long time for the display devices to adjust the white balances.